Testosterone Injectable Suspension »Testosterone Injectable Suspension is a sterile suspension of Testosterone in an aqueous medium.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of C19H28O2. Packaging and storage— Preserve in single-dose or multiple-dose containers,preferably of Type Iglass. USP Reference standards á11ñ USP Endotoxin RS.USP Testosterone RS. Identification— The testosterone obtained by filtration and washing,as directed in the Assay,and dried at 105to constant weight,meets the requirements for Identificationtests Aand Bunder Testosterone. Bacterial endotoxins á85ñ It contains not more than 3.5USP Endotoxin Units per mg of testosterone. Uniformity of dosage units á905ñ: meets the requirements. pHá791ñ: between 4.0and 7.5. Other requirements— It meets the requirements under Injections á1ñ. Assay— Transfer an accurately measured volume of previously well-mixed Injectable Suspension,equivalent to about 100mg of testosterone,to a fine-porosity,sintered-glass filtering crucible,previously dried at 105for 1hour,and filter with suction.If the filtrate is not clear,again pass it through the same filter into a second receiver.Wash the residue in the filter with several 5-mLportions of water until 2mLof the last washing,when evaporated on a steam bath,leaves a negligible residue.[NOTE—If the Injectable Suspension is passed through the filter twice,rinse the first receiver with the portions of water before passing them through the filter.]Dry the crucible and the collected testosterone at 105for 1hour.Completely dissolve the testosterone with five 25-mLportions of methanol,passing each portion through the crucible under gentle suction,and transfer the combined methanol solution to a 200-mLvolumetric flask.Rinse the crucible and receiver with two 25-mLportions of methanol,add the rinsings to the main solution,dilute with methanol to volume,and mix.Transfer 5.0mLof this solution to a 250-mLvolumetric flask,dilute with methanol to volume,and mix.Concomitantly determine the absorbances of this solution and a Standard solution of USP Testosterone RS,in the same medium having a known concentration of about 10µg per mLin 1-cm cells at the wavelength of maximum absorbance at about 241nm,with a suitable spectrophotometer,using methanol as the blank.Calculate the quantity,in mg,of C19H28O2in each mLof the Injectable Suspension taken by the formula: (10C/V)(AU/AS), in which Cis the concentration,in µg per mL,of USP Testosterone RSin the Standard solution,Vis the volume,in mL,of Injectable Suspension taken,and AUand ASare the absorbances of the solution from the Injectable Suspension and the Standard solution,respectively. Auxiliary Information— Staff Liaison:Clydewyn M.Anthony,Ph.D.,Scientist Expert Committee:(PA1)Pharmaceutical Analysis 1 USP28–NF23Page 1875 Phone Number:1-301-816-8139